Mobile telephone including a multi-band antenna

ABSTRACT

A multi-band antenna for use in a mobile radio telephone. The antenna includes first and second meandering conductor structures and a contact spring connecting the conductor structures to a transmitter/receiver. The meandering conductor structures and contact spring are formed as a single-piece punched and bent part, without overlapping of the components.

BACKGROUND

The present invention relates to a mobile radiotelephone including amulti-band antenna having a meandering conductor structure and a contactspring for contacting the conductor structure to atransmitting-receiving electronics device.

Mobile radiotelephones of this type can be implemented as a mobiletelephone, for example. The dimensions of the antenna of such a device,wherein antennas are now integrated into the housing on a wide scale,are restricted for reasons of design. Furthermore, this mobileradiotelephone should also be increasingly capable of operating not onlyin a single network, corresponding to a single frequency range, but alsoin a plurality of networks, corresponding to a plurality of frequencyranges. An integrated antenna is therefore required that is capable ofbeing used in two or more frequency ranges. In addition, there is arequirement that the mobile radiotelephone in question should be able tobe implemented as cost-effectively as possible with respect to itsperformance capabilities and its design.

A multi-band antenna integrated into the housing of known mobileradiotelephones consists, for example, of a plurality of partialantennas. With regard to these partial antennas, these are eithercylindrically symmetric helical wire structures or planar antennas thatare preferably implemented on circuit boards. However, since their basicforms do not compound to the shape of the housing, which typically has agenerally elliptical cross-section, such antennas require a relativelyhigh amount of space in the housing. For this reason, the requirementsrelating to the design of the mobile radiotelephone cannot be compliedwith or can only be complied with inadequately, given the smalldimensions.

A known method for implementing a multi-band antenna of the mobileradiotelephone in question by meandering structures on a flexibleprinted circuit board material. A multi-band antenna of this typeexhibits great flexibility as a result. The costs that result for theflexible base material and the requisite contact to the flexibleconductor material, however, are a multiple of the costs of theaforementioned nonflexible antenna.

SUMMARY

An example of a multi-band antenna for use in a mobile radio telephoneis disclosed. The antenna includes a first meandering conductorstructure, second meandering conductor structure and a contact springconfigured to connect the first and second conductor structures to atransmitting receiving electronics device. The first and secondmeandering conductor structures and the contact spring are formed as asingle-piece punched and bent part where the first, second meanderingconductor structure, second meandering conductor structure and contactspring do not overlap one another. Additionally, the first and secondmeandering conductors are located in respective laterally displacedplanes.

In another disclosed example, a multi-band antenna is disclosed wherethe first meandering conductor structure and second meandering conductorstructure are located on respective first and second curved surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a side elevation view of a disclosed multi-bandantenna of a mobile radiotelephone.

FIG. 2 illustrates a side elevation view of another disclosed multi-bandantenna of a mobile radiotelephone.

FIG. 3 illustrates a diagrammatic form of the reflection coefficient ofthe multi-band antenna illustrated in FIG. 1, wherein the frequencybands covered by the antenna are shown with dashed lines.

DETAILED DESCRIPTION OF THE PRESENT EXAMPLES

In FIG. 1, a multi-band antenna is denoted generally by the referencenumber 10. With regard to the multi-bend antenna 10, this is asingle-piece punched and bent part including a meandering conductorstructure with a first meandering conductor structure 11, a secondmeandering conductor structure 12 and a contact spring 13. The twomeandering conductor structures 11, 12 and the contact spring 13 arelocated relative to one another in such a way that there is no overlapin their development (in a developed state). The development of thefirst meandering conductor structure 11 is formed in planar fashion inthe same way as the second meandering conductor structure 12, and thesetwo meandering conductor structures are situated in two laterallydisplaced planes in their developed state and are connected with oneanother with a connecting piece 14 that is positioned at right angles tothe meander planes. The contact spring 13 is located in the area of theconnecting piece 14 and represents an extension of this connectingpiece.

The first meandering conductor structure 11 includes a first meandersection 15, starting from the connecting piece 14, with two arms 16 and17 running parallel to one another. The first meander section 15 isfollowed by a second meander section 18, which includes two arms 19 and20 running parallel to one another and also parallel to the arms 16, 17of the first meander section 15. The second meander section 18 isconnected to the first meander section 17 by a crosspiece 21. The secondmeander section is followed, connected by a crosspiece 22, by a thirdmeander section 23, which includes two arms 24, 25 running parallel toone another and also parallel to the aforementioned arms 16, 17 and 19,20. The third meander section 23 is followed by, a fourth meandersection 26, which is connected to the preceding meander section 23 by acrosspiece 27 and includes two arms 28 and 29 that run parallel to oneanother and also to the aforementioned arms. The fourth meander section26 is connected by a crosspiece 30 to a following fifth meander section31, which, like the preceding meander sections, includes two arms 32 and33 in parallel alignment. The fifth meander section 31 runs into aterminating arm 34 extending in the meander direction and bent inwardsby 90°.

The mutual spacing of the five meander sections 15, 18, 23, 26, and 31is chosen to be different in each case in the same way as is therelative spacing of their arms 16, 17, 19, 20, 24, 25, 28, 29, 32 and33. These spacings and their sequence are optimized in favor of thefrequency range to be covered by the antenna.

The second meandering conductor structure 12 has a less complexstructure than the first meandering conductor structure 11 and includesa single meander section 35 located at a distance above the terminatingarm 34 of the first meander section 11 and has arms 36, 37 runningparallel to one another and also to the arms of the first meanderingconductor structure 11. The meander section 35 is connected by means ofits lower arm 36 by a further, long connecting piece 38 to the contactspring 13 and the connecting piece 14.

Three frequency ranges total are defined as a result of the meanderingconductor structures 11, 12 of the multi-band antenna 10. The pertinentreflection coefficient of the multi-band antenna 10 is shown in FIG. 3as a solid line and generally denoted by the reference number 38. Thethree frequency ranges or bands of the multi-band antenna 10,corresponding to the EGSM band, the PCN band and the PCS band, are shownin dashed lines and are denoted by the reference numbers 39, 40 and 41.

FIG. 2 shows another example of the multi-band antenna 10 shown in FIG1. The multi-band antenna 10 shown in FIG. 2 essentially has the samebasic structure as the multi-band antenna 10 shown in FIG. 1, but withthe difference that the development of the meandering conductorstructures is not located in flat planes but on curved surfaces and withthe difference that the first meandering conductor structure 11 includesnot five, but simply three meander sections. The second meanderingconductor structure 12′ on the other hand is configured corresponding tothe first meandering conductor structure 11. The same elements of theantenna 10′ are denoted by the same reference numbers as for the antenna10, for which reason a detailed description of these elements isunnecessary. A further difference distinguishing the antenna 10′ fromthe antenna 10 is the fact that the distances between their meandersections and also the distances between the arms of the meander sectionsare different, with the result that a different reflection coefficientis produced for the antenna 10′ than is the case with the antenna 10.

Because the meandering conductor structure and the contact sprig of thedisclosed antenna are formed as a single part, which is non-overlappingin its development, this antenna can be manufactured without anydifficulties and cost-effectively by means of a single punchingoperation, which is then followed simply by an additional bendingoperation, if necessary. Since the disclosed single-piece punched andbent part can be shaped as desired within broad limits, it can beadapted without any difficulties to the desired design of the mobileradiotelephone without needing to pay attention to the structure of theantenna.

A further advantage of the disclosed antenna consists in the fact thatit can be produced with a high speed of manufacture and therefore withlow manufacturing costs because it is possible to revert to using thestandard punch and bend method. Since the multi-band antenna is designedas a single-piece punched and bent part, there is no need for separatemanufacture and provision of the antenna spring.

The two meandering structures, of which there are at least two, of themulti-band antenna formed as a single-piece punched and bent part areconnected in parallel and arranged so close to one another that a clearcoupling is achieved. This results in the overall volume of themulti-band antenna being kept to a minimum. In this situation, usage ofthe distributed partial inductances and capacitances of the meanderingstructures is optimized with the result that the antenna can be operatedreliably in a plurality of frequency rages. Through optimization, it ispossible to deploy the multi-band antenna in the vicinity of its firstresonant frequency for one of the target frequency bands (e.g., GSM)while close to its second resonant frequency it functions in such abroadband manner that this allows an application in the case of twofurther frequency bands (e.g., PCN and PCS).

A further advantage of the multi-band antenna formed as a single-piecepunched and bent part consists in the fact that a rated impedance of 50Ohms can be implemented without any difficulties, with the cult thatthis antenna can be operated without an additional adapter network,which is required in the prior art. This ensures that the disclosedantenna can be operated without suffering those losses which areunavoidable as a result of adapter elements.

1. A multi-band antenna for use in a mobile radiotelephone, the antennacomprising: a first meandering conductor structure; a second meanderingconductor structure; and a contact spring configured to connect thefirst and second conductor structures to a transmitting-receivingelectronics device, wherein the first and second meandering conductorstructures and the contact spring are formed as a single-piece punchedand bent part where the first and second meandering conductor structuresand contact spring do not overlap one another, and wherein the first andthe second meandering conductors are located in respective laterallydisplaced planes.
 2. A multi-band antenna according to claim 1, whereinthe first and second meandering conductor structures comprise respectivemeanders of differing configuration in order to provide multi-bandfunctionality of the multi-band antenna.
 3. A multi-band antennaaccording to claim 1, wherein the meandering conductor structures arelocated beside one another.
 4. A multi-band antenna according to claim3, characterized in that the meanders comprise a different number and/orshape of meander sections.
 5. A multi-band antenna according to claim 4,further comprising a triple-band antenna wherein the second meanderingconductor structure connects with an end of the first meanderingconductor structure furthest from the input/output point, and a secondconnecting piece connected to the second meandering conductor structureruns along a long side of the first meandering conductor structure.
 6. Amulti-band antenna for use in a mobile radiotelephone, the antennacomprising: a first meandering conductor structure; a second meanderingconductor structure; and a contact spring configured to connect thefirst and second conductor structures to a transmitting-receivingelectronics device, wherein the first and second meandering conductorstructures and the contact spring are formed as a single-piece punchedand bent part where the first and second meandering conductor structuresand contact spring do not overlap one another, and wherein the firstmeandering conductor structure is located on a first curved surface andthe second meandering conductor structure is located on a second curedsurface.
 7. A multi-band antenna according to claim 6 wherein themeandering conductor structures are connected to one another with afirst connecting piece at an antenna signal input/output point.
 8. Amulti-band antenna according to claim 7, wherein one of the first andsecond meandering conductor structures is tuned to a first resonantfrequency while the other of the first and second meandering conductstructures is turned for greater broadband basis to a second and a thirdresonant frequency.
 9. A multi-band antenna according to claim 6 whereinthe first and second meandering conductor structures are configured in aplanar fashion.
 10. A multi-band antenna according to claim 6 whereinthe first and second meandering conductor structures are configured in acurved fashion.
 11. A multi-band antenna according to claim 6 whereinthe first and second meandering conductor structures have a ratedimpedance of 50 Ohms overall.
 12. A multi-band antenna according toclaim 11, wherein the first and second meandering conductor structurescomprise respective meanders of differing configuration in order toprovide multi-band functionality of the multi-band antenna.
 13. Amulti-band antenna according to claim 11, wherein the meanderingconductor structures are located beside one another.
 14. A multi-bandantenna according to claim 11, characterized in that the meanderscomprise a different number and/or shape of meander sections.
 15. Amulti-band antenna according to claim 11, wherein the meanderingconductor structures are connected to one another with a firstconnecting piece at an antenna signal input/output point.
 16. Amulti-band antenna according to claim 11, further comprising atriple-band antenna wherein the second meandering conductor structureconnects with an end of the first meandering conductor structurefurthest from the input/output point, and a second connecting piececonnected to the second meandering conductor structure runs along a longside of the first meandering conductor structure.
 17. A multi-bandantenna according to claim 11, wherein one of the first and secondmeandering conductor structures is tuned to a first resonant frequencywhile the other of the first and second meandering conduct structures isturned for greater broadband basis to a second and a third resonantfrequency.
 18. A multi-band antenna according to claim 11 wherein thefirst and second meandering conductor structures are configured in aplanar fashion.
 19. A multi-band antenna according to claim 11 whereinthe first and second meandering conductor structures are configured in acurved fashion.